A time-dependent constitutive law for materials with microstructural evolution

A material model is proposed which captures microstructural changes in mate rials with phase transformations. The micromechanical concept of a represen tative cell is used to derive evolution equations for microstructural varia bles and relations for the overall material behaviour. The microstructural variables are directly related to the geometry of the microstructure. Assum ing an elliptical inclusion with eigenstrains and an interface energy the a ttempt is made to model the micromechanics rather accurately. Results are s hown for material parameters that mimic nickel base alloys at high temperat ures. Macroscopic creep occurring due to formation and movement of dislocat ions is not considered. (C) 2001 Elsevier Science Ltd. All rights reserved.